Return-Path: Sender: (Marvin Kaye) To: lml@lancaironline.net Date: Sat, 03 Jan 2004 13:56:56 -0500 Message-ID: X-Original-Return-Path: Received: from hestia.email.starband.net ([148.78.247.131] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2915588 for lml@lancaironline.net; Sat, 03 Jan 2004 12:07:54 -0500 Received: from regandesigns.com (vsat-148-63-101-227.c002.t7.mrt.starband.net [148.63.101.227]) by hestia.email.starband.net (8.12.9/8.12.9) with ESMTP id i03H7KbY010728 for ; Sat, 3 Jan 2004 12:07:24 -0500 X-Original-Message-ID: <3FF6F6C7.8030906@regandesigns.com> Disposition-Notification-To: Brent Regan X-Original-Date: Sat, 03 Jan 2004 09:07:19 -0800 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Subject: Re: IVP Accumulator orientation & Hydraulic hoses Content-Type: multipart/alternative; boundary="------------080002030506010902020303" This is a multi-part message in MIME format. --------------080002030506010902020303 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Tom Asks: <<<<< I have noticed in several pictures I've seen that some builders have mounted the hydraulic system accumulator horizontal rather than vertical like the manual suggests. Does this thing work the same, regardless of orientation? >>> Yes. It has an internal bladder that separates the N2 from the oil. <<<<<< Second question, I was on the website for a professional builders assist shop (the one Rob Wolf used) and spotted a IV they were finishing. They noted they had to replace all the hydraulic plumbing and it is shown now done in flexible hose instead of aluminum tubing. Is there a problem with the aluminum tubing being used as the factory suggests? >>>>> Well, Aluminum tubing does have the "problems" of being lighter, stronger, smaller, it has no age limit and can be easily fabricated. The only down side is that it can corrode and, if subjected to flexing, fatigue. In my IV, I made an effort to eliminate hoses where ever possible. The only hoses aft of the firewall are for the brake master cylinders, the flap actuator and the DH hoses at the gear legs for the brakes. Nine years and over 800 flight hours later I have not had a single hydraulic system leak or failure. Of course there is that silly notion that aluminum tubing is what everybody else uses, so....... Regarding hoses, I did NOT use the screw on fittings supplied with the kit. Instead I had all the hoses fabricated at Sacramento Sky Ranch. They have an unbelievable guarantee that if you buy a hose from them you can return it for a replacement for any reason, even if you told them to make it the wrong length!! Teflon with an aluminum overbraid and integral fire sleeve (firewall forward) is the best choice as it too does not have a life limit. IMHO ALL hoses must be pressure tested to 1.5 rated pressure (burst rating on hoses is 3X rated) and flushed before installation. Many of the problems associated with hydraulic pump cycling are due to contamination. There are some detailed threads in the archive on hoses et al. Regards Brent Regan --------------080002030506010902020303 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Tom Asks:
<<<<<
I have noticed in several pictures I've seen that some builders have mounted

the hydraulic system accumulator horizontal rather than vertical like the
manual suggests. Does this thing work the same, regardless of orientation?

>>>

Yes. It has an internal bladder that separates the N2 from the oil.

<<<<<<

Second question, I was on the website for a professional builders assist
shop (the one Rob Wolf used) and spotted a IV they were finishing. They
noted they had to replace all the hydraulic plumbing and it is shown now
done in flexible hose instead of aluminum tubing. Is there a problem with
the aluminum tubing being used as the factory suggests?

>>>>>

Well, Aluminum tubing does have the "problems" of being lighter, stronger, smaller, it has no age limit and can be easily fabricated. The only down side is that it can corrode and, if subjected to flexing, fatigue. In my IV, I made an effort to eliminate hoses where ever possible. The only hoses aft of the firewall are for the brake master cylinders, the flap actuator and the DH hoses at the gear legs for the brakes. Nine years and over 800 flight hours later I have not had a single hydraulic system leak or failure. Of course there is that silly notion that aluminum tubing is what everybody else uses, so.......

Regarding hoses, I did NOT use the screw on fittings supplied with the kit. Instead I had all the hoses fabricated at Sacramento Sky Ranch. They have an unbelievable guarantee that if you buy a hose from them you can return it for a replacement for any reason, even if you told them to make it the wrong length!! Teflon with an aluminum overbraid and integral fire sleeve (firewall forward) is the best choice as it too does not have a life limit.

IMHO ALL hoses must be pressure tested to 1.5 rated pressure (burst rating on hoses is 3X rated) and flushed before installation. Many of the problems associated with hydraulic pump cycling are due to contamination.

There are some detailed threads in the archive on hoses et al.

Regards
Brent Regan

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